The Elecraft K2 is an all-band HF rig, covering 80m through 10m. It is my goal to find an easy-to-deploy 80-10m antenna for use in the field with during my field operations. Because I began this quest while I had the Index Labs QRP Plus, in places this page still refers to my QRP Station in a Bag.

The following descriptions are not necessarily presented in chronological order because my experiments with the various antennas overlapped.

I originally carried separate dipoles for 20 and 40 meters. These dipoles are built with plexiglass center insulators and button end insulators, and each dipole has an integral thirty-foot RG-174 feedline. While these dipoles don't require the use of a tuner, they only cover the two bands, and two antennas have to be strung to operate on those two bands. (photo of antenna & a detail view)

In my quest to find an easy-to-deploy all-band antenna, I experimented extensively with the W3EDP wire antenna. The W3EDP, a variation of a true Zepp, is an interesting antenna, and one that I had high hopes for. It is described in Practical Wire Antennas by John D. Heys, G3BDQ; additional information on the W3EDP can be found in my Archives and Articles and in the article The FFD Antenna: A Field-Friendly Doublet, with Notes on Related Designs by Charlie Lofgren, W6JJZ.

The W3EDP consists of an 85' wire and a 17' wire that's sometimes called a "counterpoise". The counterpoise isn't connected for 80m or for 10m, but is connected for 15m, 20m, and 40m. The W3EDP is very easy to deploy--it needs only one elevated support, doesn't need a separate feedline, and packs up really small.

My initial trials of the W3EDP were using the MFJ-901B/HM-9 combination. I was able to successfully use the the W3EDP on 20m and 40m over the year that I experimented with it, on several operating events as well as on two trips away from home. Following the recommendations (article) of Charlie Lofgren, W6JJZ, I tried configuring my W3EDP such that the 17' wire was half of a parallel feedline, using 0.75" x 1.5" sheet styrene pieces as separators. However, when I tried this arrangement as an Inverted-L (using a sliding "button" insulator on the radiating element) from a cabin on Presque Isle, Michigan, I had trouble getting a good match on 20 and 80 meters. On subsequent trials with the 17' counterpoise lying on the ground it tuned easily on 20 and 40 meters, but I couldn't get a match on 80 meters. Clearly, the W3EDP/MFJ-901B antenna system was not the ideal all-band antenna system.

The arrival of the LDG Z-11 QRP Autotuner changed everything. The Z-11 easily tunes the W3EDP on 10, 15, 20, 40, and 80m through the homebrew 4:1 balun. I used this antenna from my billet at Rickenbacker Air National Guard Base during the month of June, 2003, suspending the 85' portion of the antenna between my third-floor window and the outside staircase of the neighboring building, allowing the 17' component to hang out the window. The tuner with balun easily tuned the antenna on all bands tried and QSOs were successfully made on 40m. I have also used the W3EDP/Z-11/balun combination in the field. I operated the 2003 E-PA QRP "TAC" Contest with the W3EDP/Z-11 antenna system, this time with the 85' portion extended in an inverted-L arrangement between two trees and the 17' component lying on the ground beneath the radiator. Again, the tuner easily tuned the antenna on all the bands tested and QSOs were successfully made on 20m and 40m despite poor band conditions. The W3EDP/Z-11 antenna system is a viable all-band antenna system. It's easy to deploy, tunes easily, and covers all the bands of interest.

I have 100' of teflon-coated wire wound onto an inexpensive plastic camping-style clothesline reel (photo). My plan with this wire antenna is to spool out as much as the available supports allow and operate it against the 17' W3EDP counterpoise. I have not yet tried this antenna in the field.

After reading the article Antennas and the QRP Operator by Jim Thompson, W4THU, in Low Power Communications, Volume 2 (edited by Rich Arland, K7YHA), I built a 20m Extended Double Zepp. This is an 86' foot doublet and is fed with balanced line. W4THU claims the 20m EDZ will provide 4dB gain over a 1/2-wave dipole on 20m, performance similar to a dipole cut for 40m and 80m on those bands, and useful gain over a dipole on 10m and 15m. I built my first version with lightweight hookup wire for the elements, used military buttons for the center and end insulators, and fed it with Radio Shack "Ultra Low Loss" 300-ohm TV twinlead. During the 1998 QRP ARCI Fall QSO Party this antenna worked very well on 15, 20, and 40m, and also tuned easily on 10m and 80m. After the event, I "ruggedized" the EDZ with a 35mm film-canister center insulator.

After using both the portable 20m EDZ and a one installed permanently at home, I decided the 20m EDZ provides nodes that are too narrow for general use and that the QRP Station in a Bag needs an antenna with more omni-directional coverage. Towards that end, in preparation for the 1999 Arizona ScQRPions "Freeze Your B___ Off", I changed the 20m EDZ (now fed with 300-ohm ladderline) into a 70' doublet. I chose the 70' length based on the chart of "lengths to avoid" in Practical Wire Antennas. Unfortunately, at FYBO, I found that the antenna could be tuned only on 40m with the MFJ-901B, so I cut about three feet off of both ends which allowed the antenna to tune well on 15, 40, and 80m, but it still wouldn't tune on 20m.

Ron Weisen, WD8PNL, described a field-portable doublet antenna in this email to me. His doublet is made with clear-insulation speaker wire which his tests have shown to have very low loss when used as a feedline. Ron has reported good results with this flexible and inexpensive antenna.

Doug Hendricks, KI6DS, and Howard Zehr, N9AHQ, describe similar field-portable doublets that are light enough to be supported by a 20-foot "Black Widow" fishing pole. Their designs use computer ribbon-cable and are described in these articles:

NorCal Doublet by Doug Hendricks, KI6DS, at NorCal
Crappie Portable Antenna by Howard Zehr, N9AHQ, at AmQRP
Crappie Portable Antenna by Howard Zehr, N9AHQ, at NorCal

In an email to me, KI6DS wrote that the first 150 QSOs with his doublet at 20' included forty-four states and six DX countries. Tests conducted to determine the loss-qualities of ribbon-cable when used as feedline showed that it is, in his words, "lossy, but not too". His doublet was rugged enough to stay up at his home QTH for a couple of years before falling down. (For a different view on zip cord feedline, here is an article by KK6MC/5 describing zip cord feedline losses.)

I had intended to build a doublet this type, using either ribbon-cable or zip-cord as the feedline and elements, but upon looking through my wire-box, I found that I didn't have a enough of either material. I did find, however, a marvelous military-surplus "Dipole Fixture" (#1540368) which included 30' of excellent low-loss 72-ohm military twinlead, so I built a doublet using the 72-ohm twinlead as the feedline, 22' pieces of ribbon-cable as the legs, a film canister for the center-insulator, a fishing-swivel to hang the thing, and military "BDU" buttons as end-insulators. The "Dipole Fixture" itself was designed to serve as a center-insulator, center support, strain-relief, and wire reel but is far too heavy to hang from a "Black Widow" 20' fiberglass fishing pole. However, it serves beautifully as a tangle-free spool for transport of the doublet elements and feedline.

Here are photos of the completed 44' doublet:

The "Dipole Fixture", with elements and feedline wrapped on it
The factory-insulated plugs on the radio-end of the feedline
The film-canister center-insulator
The button end-insulators

I've erected this antenna, supporting it in the center with the Black Widow, and verified that the Z-11 will tune it on all the MF/HF bands. (I don't expect, that this 44' antenna would radiate well on 160m, but it seems the rig will be happy to pump RF into it!) I used this antenna during the 2005 Freeze Your B___ Off contest. It worked very well on 20m and 40m. No activity was heard on 80m during this daytime contest, so I don't know yet how the doublet works on 80m.

I've found that the LDG AT-100Pro won't tune the 44' doublet on 80m. To solve this, I've increased the overall length of the doublet to 55', but found that the AT-100Pro still won't tune it on 80m.

The Black Widow supports the doublet as an inverted-vee without problem, but there is significant bowing at the top of the pole. I might try supporting the legs of this antenna with dental floss as described here.)

I am curious as to whether a NorCal Doublet (built with one continuous length of computer ribbon-cable and no center-insulator) would cause less bowing of the Black Widow. I also remain curious about the feedline-loss of antennas made of ribbon-cable. Eventually, I hope to run some tests on ribbon cable as a feedline and possibly make a NorCal Doublet to test. In the meantime, the doublet, as constructed, will remain a part of the QRP Station in a Bag and is now my primary field-portable antenna.

I built the W6MMA Vertical using a 20' Black Widow telescoping fiberglass crappy pole from Cabelas and Vern Wright's 80m coil kit. I had very high hopes for this 80-10m no-tuner-needed self-supporting vertical antenna. The W6MMA has proven to be very easy to deploy, and requires no supporting mast or tree. I successfully used this antenna in the 1999 E-PA "TAC", the 2000 FYBO, and the 2000 ARRL Field Day.

Initially I used radials made from computer ribbon cable. These ribbon cables store very well and are relatively tangle-free but are fragile. I've since replaced these with radials made from split #18 zip cord--white for easy visibility--and have found these to be flexible enough that tangling hasn't (yet) been a problem.

The only real problem with this antenna is that adjusting it after band changes seems to require two people--one to key the rig and read the SWR bridge, and one to adjust the sliding tap. If I owned an antenna analyzer this wouldn't be so much of a problem.

I have had a really difficult time getting string and wire into trees. I've tried using small lead weights, half-full water bottles, and tennis balls. I would like to try to build a slingshot system such those described by Bill Jones, KD7S, and Russ Carpenter, AA7QU, in the following articles:

The HyLaunch, Build a Compact, Integrated Antenna Launching System
Antenna Launching for Serious Practitioners (and correct URL for the reel)

The Throw Bag/Slick Line technique as described by John Kalotai, N1OLO, is also worthy of consideration:

In the Bag: Throwing Antenna Woes to the Wind

Doc, W5TB, sent me an email regarding his version of the N1OLO Throw Bag:

W5TB Throw-Rope

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